Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, touch panels, joysticks, touch screens and the like. Touch screens, in particular, are becoming increasingly popular because of their ease and versatility of operation as well as their declining price. Touch screens can include a touch panel, which can be a clear panel with a touch-sensitive surface. The touch panel can be positioned in front of a display screen so that the touch-sensitive surface covers the viewable area of the display screen. Touch screens can allow a user to make selections and move a cursor by simply touching the display screen via a finger or stylus. In general, the touch screen can recognize the touch and position of the touch on the display screen, and the computing system can interpret the touch and thereafter perform an action based on the touch event.
Touch panels can include an array of touch sensors capable of detecting touch events (the touching of fingers or other objects upon a touch-sensitive surface). Future panels may be able to detect multiple touches (the touching of fingers or other objects upon a touch-sensitive surface at distinct locations at about the same time) and near touches (fingers or other objects within the near-field detection capabilities of their touch sensors), and identify and track their locations. Examples of multi-touch panels are described in Applicant's co-pending U.S. application Ser. No. 10/842,862 entitled “Multipoint Touchscreen,” filed on May 6, 2004 and published as U.S. Published Application No. 2006/0097991 on May 11, 2006, the contents of which are incorporated by reference herein.
Proximity sensors are another type of input device capable of detecting hover events (the no-touch, close proximity hovering of fingers or other objects above a surface but outside the near-field detection capabilities of touch sensors) as well as touch events. Proximity sensors can be employed singly or in a few important locations in a computing system, or can be arranged in panels. Proximity sensor panels may be able to detect multiple instances of hovering referred to herein as multi-hover events (the hovering of fingers or other objects above a surface at distinct locations at about the same time). Examples of a proximity sensor, a proximity sensor panel, a multi-hover panel and a computing system using both a multi-touch panel and proximity sensors are described in Applicant's co-pending U.S. application Ser. No. 11/649,998 entitled “Proximity and Multi-Touch Sensor Detection and Demodulation,” published as U.S. Patent Application Publication No. 2008/0158172, filed on Jan. 3, 2007, the contents of which are incorporated by reference herein.
Ambient light sensors are yet another type of input device capable of detecting various levels of ambient light. Ambient light sensors can be employed singly or in a few strategic locations in a housing of a computing system.
Proximity sensors, proximity sensor panels, and ambient light sensors can be employed either alone or in combination with multi-touch sensor panels as input devices for computing systems. In addition, as mentioned above, a display screen can be located beneath the sensor panel. A user interface (UI) algorithm can generate a virtual keypad or other virtual input interface beneath the sensor panel that can include virtual buttons, pull-down menus and the like. By detecting touch or hover events at locations defined by the virtual buttons, the UI algorithm can determine that a virtual button has been “pushed.” The magnitude of the analog channel output values, indicating the “degree” of touch or hover, can be used by the UI algorithm to determine whether there was a sufficient amount of touch or hover to trigger the pushing of the virtual button.
Because the proximity sensors, proximity sensor panels, ambient light sensors, and display screens all require some access to the outside world to detect fingers or objects, or pass IR light or visible light, any housing incorporating one or more of these devices must provide apertures for such access. Often, openings are formed in an outer cover of the housing to provide this access. However, because these openings represent discontinuities in the otherwise uniform surface of the cover, assembly difficulties can arise. Furthermore, these openings and discontinuities can cause the outer surface to look “busy” or overly complicated, and detract from the aesthetic appearance of the computing device.